Longitudinal characterisation of haematological and biochemical parameters in cancer patients prior to and during COVID-19 reveals features associated with outcome

•Pre-infection haematological/biochemical characteristics are not associated with COVID-19 severity.•Significant haematological/biochemical changes occur upon infection with heterogeneity in response observed.•High not low neutrophils were associated with oxygen requirement and COVID-19 mortality – GCSF should be used with caution.•Age, haematological cancer, high neutrophil:lymphocyte ratio, CRP and low albumin were significant predictors of...